The crane is based on the Supermodel 04 plan for the Boom and travelling Gantry, but it has been modified somewhat to accommodate the parts I had available.
I have used the large tooth quadrants as the turntable. The model is driven by one of Dave Taylor’s motors through the original plan gearbox which drives all four functions.
I have got to further reduce the final drive gearing to the gantry as the weight of the crane is too much for the current gearing (it won’t drive!).